Expression of CDKN1C (p57) and CDKN1b (p27). Gene expression of CDKN1C (p57) and CDKN1b (p27) in the LT-HSC compartment was measured with quantitative RT-PCR analysis. RNAs were isolated from sorted LT-HSCs, ST-HSCs, and MPP cells from primary Dmtf1-KO or WT mice. Relative expressions are shown normalized to gene expression in WT MPP cells (mean ± SD, n = 3). *P < .05.